Blue nevus (a blue nevus Yadassona-Tich) — the acquired pigmentary new growth of skin of the small size having characteristic dark blue or blue coloring. As a rule, such education happens single, but also a multiple blue nevus in some cases meets. This nevus belongs to good-quality, but melanomoopasny educations. In rare instances it can malignizirovatsya with development of a melanoma. In treatment of a blue nevus usually adhere to waiting tactics and carry out removal of a nevus only at its significant increase or other changes which can be a sign of malignant regeneration.
The blue nevus arises at people of any age group, but most often appears during puberty. It is characterized by slow growth and does not cause any subjective feelings therefore the long time can remain unnoticed at the patient. The blue nevus occurs among women more often than among men.
Symptoms of a blue nevus
The blue nevus represents accurately delimited small knot of an oval, rounded or spindle-shaped shape located in skin. It usually has the size to 1 cm in the diameter, a nevus up to 3 cm was in some cases observed. Dark blue, blue or blue-black coloring of a nevus happens uneven and is caused by congestions of a large amount of melanin in deep layers of skin. The nevus can tower a little over the surface of skin or not act over it at all. Looking at it, to develop impression that under skin there is some foreign matter. A surface of a blue nevus smooth without growth of hair, a consistence dense and elastic.
The nevus on the back of feet and brushes, on shins and forearms, on buttocks settles down, is more rare — on a face or in a mouth. Usually it does not cause an itch, morbidity or any other feelings. The blue nevus happens the discomfort reason only if it is located in the place where it is constantly injured. It is possible to suspect transformation of a blue nevus in a melanoma on the changes happening in it: the accelerated growth, change of color, decrease in clearness of contours, emergence of unpleasant feelings in the field of a nevus.
Distinguish a simple and cellular form of a blue nevus, and also the combined nevus. The simple blue nevus is a single small knot to 1 cm in the diameter with a smooth surface and a dense and elastic consistence. It can have any coloring in the range from light gray to black-blue. The favourite arrangement of such nevus — a neck, a face and hands, but is possible its emergence on a trunk, mucous a mouth, a neck of a uterus and a vagina.
The cellular blue nevus has the big sizes (1,5-3 cm) and dark blue coloring, its surface can be uneven. Because of these features it is often taken for a malignant new growth. In half of cases the cellular nevus comes to light on a waist or buttocks, less often it settles down on a back surface of feet and brushes. The combined nevus is a combination of a simple blue nevus with a vnutridermalny, boundary or difficult pigmentary nevus.
Diagnostics of a blue nevus
The small sizes, the expressed otgranichennost and characteristic color in many cases allow to assume the diagnosis of a blue nevus at once. For more exact diagnostics Dermoscopy — visual studying of depth, borders and structure of a nevus is carried out at increase. The Siaskopichesky research allows to define the nature of distribution of melanin and to study structure of a nevus. The blue nevus is differentiated with a boundary nevus, dermatofibromy, a melanoma. In difficult a case the ultrasonography of a skin new growth determining depth of germination and malignant infiltrative growth can be applied to differential diagnostics with a melanoma.
The histologic research conducted after removal of a blue nevus reveals congestions of melanotsit in average and lower layers terms. The congestion of the cages filled with melanin is characteristic of a simple blue nevus. The cellular nevus is presented by cages of the big size with the small maintenance of a pigment. These cages are grouped in the islands divided by soyedinitelnotkanny crossing points.
Treatment of a blue nevus
At a quiet current of a blue nevus without sharp changes of its sizes and appearance removal of education is not required. The owner of a nevus should be observed and have periodic examinations at the dermatologist or a dermatoonkolog. Surgical treatment is necessary and when the blue nevus is located so that there is its continuous traumatizing which can provoke its malignant transformation in a melanoma. Removal of a blue nevus can be carried out by a radio wave method, electrothermic coagulation or a kriodistruktion. Apply also removal of a nevus the laser. In doubtful cases when there are difficulties in differentiation of a blue nevus from a melanoma, or at emergence of the changes of a nevus speaking about a possible malignization carry out surgical excision of a nevus. Excision of a nevus is carried out together with hypodermic fatty cellulose and the site of healthy skin 5-8 mm wide from visible border of a nevus. During removal of a nevus on a face for the best cosmetic effect width of the occupied site of healthy skin can be reduced to 3-5 mm. The remote nevus surely is exposed to a histologic research.